Jump to content
speccery

Erik's Tiny PEB

Recommended Posts

Definitely go slow for a while. This one doesn't let go of the body quickly. . .or cleanly. Some side effects don't become obvious for a month or more (like weakening of the heart muscle).

  • Like 1
  • Sad 1

Share this post


Link to post
Share on other sites
On 3/6/2021 at 11:21 AM, speccery said:

 I contracted COVID some time ago, still fighting the disease. It’s now day 9. I think this is the mild version (so far) but with so many days on this, it is a bit consuming. At least I got my appetite back a couple of days I ago, hopefully it’s a sign of something. But the fever keeps me unable to

do much, even if it isn’t too high.
 

The only TI related thing I have done is that I received this week a hard copy of @Lee Stewart’s fbForth manual which I ordered sometime ago. I haven’t read it yet, but having a real manual is nice and very exceptional.

Glad you are feeling at least a little better and it wasn't a serious case!!  Just keep an eye on yourself and try not to over do it for a while.

  • Like 2

Share this post


Link to post
Share on other sites

all the best from my side as well to you Erik!

I read the last months posts of this thread and only want to mention something about your possibility to load a file (cartridge) into the >6000  - >7FFF memory area.

There you mentioned it is not write protected and therefore might act as 8K ram slot.

While this write possibility is wanted in most places please consider

- there are cartridges that use writing to certain memory addresses in that area in order to switch their rom banks.

- there are cartridges that do a write because of a bug, which is not making an impact if the cartridge space is write protected (like on the actual hardware with an actual cartridge).

- there is Mini Memory, which is (if I am right) also having some special writes for its functionality. Which is one of the few original cartridges actually using part of this address range to store data.

 

Enjoy working on these projects, but also take it easy with your recent infection.

 

Edited by kl99
  • Like 2

Share this post


Link to post
Share on other sites
8 hours ago, kl99 said:

all the best from my side as well to you Erik!

I read the last months posts of this thread and only want to mention something about your possibility to load a file (cartridge) into the >6000  - >7FFF memory area.

There you mentioned it is not write protected and therefore might act as 8K ram slot.

While this write possibility is wanted in most places please consider

- there are cartridges that use writing to certain memory addresses in that area in order to switch their rom banks.

- there are cartridges that do a write because of a bug, which is not making an impact if the cartridge space is write protected (like on the actual hardware with an actual cartridge).

- there is Mini Memory, which is (if I am right) also having some special writes for its functionality. Which is one of the few original cartridges actually using part of this address range to store data.

 

Enjoy working on these projects, but also take it easy with your recent infection.

 

And also the Editor Assembler Super Cart with 8K ram at >6000.

  • Like 2

Share this post


Link to post
Share on other sites
15 hours ago, kl99 said:

all the best from my side as well to you Erik!

I read the last months posts of this thread and only want to mention something about your possibility to load a file (cartridge) into the >6000  - >7FFF memory area.

There you mentioned it is not write protected and therefore might act as 8K ram slot.

While this write possibility is wanted in most places please consider

- there are cartridges that use writing to certain memory addresses in that area in order to switch their rom banks.

- there are cartridges that do a write because of a bug, which is not making an impact if the cartridge space is write protected (like on the actual hardware with an actual cartridge).

- there is Mini Memory, which is (if I am right) also having some special writes for its functionality. Which is one of the few original cartridges actually using part of this address range to store data.

 

Enjoy working on these projects, but also take it easy with your recent infection.

 

I think there are even a couple that write to that space on purpose and then check the value there--as a protection mechanism. If the value is the written one, the program stops, and if it is the original ROM value, it works fine.

  • Like 3

Share this post


Link to post
Share on other sites

Thanks for the comments. I am not sure if the ability to put RAM (or write protected RAM) in the cartridge space by the ET-PEB is a good idea. Without some sort of conflict detection it would be easy to have a bus conflict between the ET-PEB and a normal cartridge. But since it was such low hanging fruit, I gave it a go. I think in the current version of the CPLD I already removed that mapping.

 

I am thinking about making a new board revision of the ET-PEB. I would like to add TIPI support and replace the CPLD with a small FPGA. The FPGA would enable me to add full 1 meg of SAMS memory with ease, and the TIPI interface would be simple to bring in too. Development of fully featured file system for the ET-PEB seems to take quite bit of time, and TIPI already handles a lot of that very well. I could then use my time for other interesting features, such as adding the J1 Forth CPU in there.

 

  • Like 1

Share this post


Link to post
Share on other sites

In my SNE program, I don't want >6050->6100 touched. So I copy that data I have stored there, as it's program code. And I put a copy off to >F000. I always just grab that copy and repeatedly place it back at certain times.

This way, I don't care if it's trashed for some reason.

Because I found that I couldn't just flip a read/write switch on my memory chip.

 

Edited by GDMike

Share this post


Link to post
Share on other sites
On 3/15/2021 at 9:13 AM, kl99 said:

all the best from my side as well to you Erik!

I read the last months posts of this thread and only want to mention something about your possibility to load a file (cartridge) into the >6000  - >7FFF memory area.

There you mentioned it is not write protected and therefore might act as 8K ram slot.

While this write possibility is wanted in most places please consider

- there are cartridges that use writing to certain memory addresses in that area in order to switch their rom banks.

- there are cartridges that do a write because of a bug, which is not making an impact if the cartridge space is write protected (like on the actual hardware with an actual cartridge).

- there is Mini Memory, which is (if I am right) also having some special writes for its functionality. Which is one of the few original cartridges actually using part of this address range to store data.

 

Enjoy working on these projects, but also take it easy with your recent infection.

 

Thanks @kl99!

Yes it's true that cartridge area, if supported, needs to have write protection. Actually in both my FPGA and StrangeCart projects the cartridge space is write protected, and writes to this space cause cartridge bank switches based on the address being written to.

 

Mini Memory is an interesting cartridge indeed, but also quite simple: >6000..>6FFF is 4K ROM, and >7000..>7FFF is 4K battery backed up RAM. The RAM area works as a normal RAM. Then of course the cartridge has some GROM too. The StrangeCart emulates all of these functions. One thing I should add to that is the ability to store the RAM region >7000..>7FFF to Flash when the system is powered off.

 

  • Like 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...